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<h1 class="title">diagramscene.cpp 示例文件</h1>
<span class="subtitle">graphicsview/diagramscene/diagramscene.cpp</span>
<!-- $$$graphicsview/diagramscene/diagramscene.cpp-description -->
<div class="descr"> <a name="details"></a>
<pre class="cpp">

  <span class="comment">/****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** &quot;Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
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  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
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  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.&quot;
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  ** $QT_END_LICENSE$
  **
  ****************************************************************************/</span>

  <span class="preprocessor">#include &quot;diagramscene.h&quot;</span>
  <span class="preprocessor">#include &quot;arrow.h&quot;</span>

  <span class="preprocessor">#include &lt;QTextCursor&gt;</span>
  <span class="preprocessor">#include &lt;QGraphicsSceneMouseEvent&gt;</span>

  DiagramScene<span class="operator">::</span>DiagramScene(<span class="type"><a href="qmenu.html">QMenu</a></span> <span class="operator">*</span>itemMenu<span class="operator">,</span> <span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent)
      : <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span>(parent)
  {
      myItemMenu <span class="operator">=</span> itemMenu;
      myMode <span class="operator">=</span> MoveItem;
      myItemType <span class="operator">=</span> DiagramItem<span class="operator">::</span>Step;
      line <span class="operator">=</span> <span class="number">0</span>;
      textItem <span class="operator">=</span> <span class="number">0</span>;
      myItemColor <span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>white;
      myTextColor <span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black;
      myLineColor <span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black;
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>setLineColor(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> <span class="operator">&amp;</span>color)
  {
      myLineColor <span class="operator">=</span> color;
      <span class="keyword">if</span> (isItemChange(Arrow<span class="operator">::</span>Type)) {
          Arrow <span class="operator">*</span>item <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>Arrow <span class="operator">*</span><span class="operator">&gt;</span>(selectedItems()<span class="operator">.</span>first());
          item<span class="operator">-</span><span class="operator">&gt;</span>setColor(myLineColor);
          update();
      }
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>setTextColor(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> <span class="operator">&amp;</span>color)
  {
      myTextColor <span class="operator">=</span> color;
      <span class="keyword">if</span> (isItemChange(DiagramTextItem<span class="operator">::</span>Type)) {
          DiagramTextItem <span class="operator">*</span>item <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>DiagramTextItem <span class="operator">*</span><span class="operator">&gt;</span>(selectedItems()<span class="operator">.</span>first());
          item<span class="operator">-</span><span class="operator">&gt;</span>setDefaultTextColor(myTextColor);
      }
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>setItemColor(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> <span class="operator">&amp;</span>color)
  {
      myItemColor <span class="operator">=</span> color;
      <span class="keyword">if</span> (isItemChange(DiagramItem<span class="operator">::</span>Type)) {
          DiagramItem <span class="operator">*</span>item <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>DiagramItem <span class="operator">*</span><span class="operator">&gt;</span>(selectedItems()<span class="operator">.</span>first());
          item<span class="operator">-</span><span class="operator">&gt;</span>setBrush(myItemColor);
      }
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>setFont(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qfont.html">QFont</a></span> <span class="operator">&amp;</span>font)
  {
      myFont <span class="operator">=</span> font;

      <span class="keyword">if</span> (isItemChange(DiagramTextItem<span class="operator">::</span>Type)) {
          <span class="type"><a href="qgraphicstextitem.html">QGraphicsTextItem</a></span> <span class="operator">*</span>item <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>DiagramTextItem <span class="operator">*</span><span class="operator">&gt;</span>(selectedItems()<span class="operator">.</span>first());
          <span class="comment">//At this point the selection can change so the first selected item might not be a DiagramTextItem</span>
          <span class="keyword">if</span> (item)
              item<span class="operator">-</span><span class="operator">&gt;</span>setFont(myFont);
      }
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>setMode(Mode mode)
  {
      myMode <span class="operator">=</span> mode;
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>setItemType(DiagramItem<span class="operator">::</span>DiagramType type)
  {
      myItemType <span class="operator">=</span> type;
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>editorLostFocus(DiagramTextItem <span class="operator">*</span>item)
  {
      <span class="type"><a href="../qtgui/qtextcursor.html">QTextCursor</a></span> cursor <span class="operator">=</span> item<span class="operator">-</span><span class="operator">&gt;</span>textCursor();
      cursor<span class="operator">.</span>clearSelection();
      item<span class="operator">-</span><span class="operator">&gt;</span>setTextCursor(cursor);

      <span class="keyword">if</span> (item<span class="operator">-</span><span class="operator">&gt;</span>toPlainText()<span class="operator">.</span>isEmpty()) {
          removeItem(item);
          item<span class="operator">-</span><span class="operator">&gt;</span>deleteLater();
      }
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>mousePressEvent(<span class="type"><a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a></span> <span class="operator">*</span>mouseEvent)
  {
      <span class="keyword">if</span> (mouseEvent<span class="operator">-</span><span class="operator">&gt;</span>button() <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton)
          <span class="keyword">return</span>;

      DiagramItem <span class="operator">*</span>item;
      <span class="keyword">switch</span> (myMode) {
          <span class="keyword">case</span> InsertItem:
              item <span class="operator">=</span> <span class="keyword">new</span> DiagramItem(myItemType<span class="operator">,</span> myItemMenu);
              item<span class="operator">-</span><span class="operator">&gt;</span>setBrush(myItemColor);
              addItem(item);
              item<span class="operator">-</span><span class="operator">&gt;</span>setPos(mouseEvent<span class="operator">-</span><span class="operator">&gt;</span>scenePos());
              <span class="keyword">emit</span> itemInserted(item);
              <span class="keyword">break</span>;
          <span class="keyword">case</span> InsertLine:
              line <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgraphicslineitem.html">QGraphicsLineItem</a></span>(<span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span>(mouseEvent<span class="operator">-</span><span class="operator">&gt;</span>scenePos()<span class="operator">,</span>
                                          mouseEvent<span class="operator">-</span><span class="operator">&gt;</span>scenePos()));
              line<span class="operator">-</span><span class="operator">&gt;</span>setPen(<span class="type"><a href="../qtgui/qpen.html">QPen</a></span>(myLineColor<span class="operator">,</span> <span class="number">2</span>));
              addItem(line);
              <span class="keyword">break</span>;
          <span class="keyword">case</span> InsertText:
              textItem <span class="operator">=</span> <span class="keyword">new</span> DiagramTextItem();
              textItem<span class="operator">-</span><span class="operator">&gt;</span>setFont(myFont);
              textItem<span class="operator">-</span><span class="operator">&gt;</span>setTextInteractionFlags(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>TextEditorInteraction);
              textItem<span class="operator">-</span><span class="operator">&gt;</span>setZValue(<span class="number">1000.0</span>);
              connect(textItem<span class="operator">,</span> SIGNAL(lostFocus(DiagramTextItem<span class="operator">*</span>))<span class="operator">,</span>
                      <span class="keyword">this</span><span class="operator">,</span> SLOT(editorLostFocus(DiagramTextItem<span class="operator">*</span>)));
              connect(textItem<span class="operator">,</span> SIGNAL(selectedChange(<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">*</span>))<span class="operator">,</span>
                      <span class="keyword">this</span><span class="operator">,</span> SIGNAL(itemSelected(<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">*</span>)));
              addItem(textItem);
              textItem<span class="operator">-</span><span class="operator">&gt;</span>setDefaultTextColor(myTextColor);
              textItem<span class="operator">-</span><span class="operator">&gt;</span>setPos(mouseEvent<span class="operator">-</span><span class="operator">&gt;</span>scenePos());
              <span class="keyword">emit</span> textInserted(textItem);
      <span class="keyword">default</span>:
          ;
      }
      <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span><span class="operator">::</span>mousePressEvent(mouseEvent);
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>mouseMoveEvent(<span class="type"><a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a></span> <span class="operator">*</span>mouseEvent)
  {
      <span class="keyword">if</span> (myMode <span class="operator">=</span><span class="operator">=</span> InsertLine <span class="operator">&amp;</span><span class="operator">&amp;</span> line <span class="operator">!</span><span class="operator">=</span> <span class="number">0</span>) {
          <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> newLine(line<span class="operator">-</span><span class="operator">&gt;</span>line()<span class="operator">.</span>p1()<span class="operator">,</span> mouseEvent<span class="operator">-</span><span class="operator">&gt;</span>scenePos());
          line<span class="operator">-</span><span class="operator">&gt;</span>setLine(newLine);
      } <span class="keyword">else</span> <span class="keyword">if</span> (myMode <span class="operator">=</span><span class="operator">=</span> MoveItem) {
          <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span><span class="operator">::</span>mouseMoveEvent(mouseEvent);
      }
  }

  <span class="type">void</span> DiagramScene<span class="operator">::</span>mouseReleaseEvent(<span class="type"><a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a></span> <span class="operator">*</span>mouseEvent)
  {
      <span class="keyword">if</span> (line <span class="operator">!</span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&amp;</span><span class="operator">&amp;</span> myMode <span class="operator">=</span><span class="operator">=</span> InsertLine) {
          <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator">&lt;</span><span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span><span class="operator">&gt;</span> startItems <span class="operator">=</span> items(line<span class="operator">-</span><span class="operator">&gt;</span>line()<span class="operator">.</span>p1());
          <span class="keyword">if</span> (startItems<span class="operator">.</span>count() <span class="operator">&amp;</span><span class="operator">&amp;</span> startItems<span class="operator">.</span>first() <span class="operator">=</span><span class="operator">=</span> line)
              startItems<span class="operator">.</span>removeFirst();
          <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator">&lt;</span><span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span><span class="operator">&gt;</span> endItems <span class="operator">=</span> items(line<span class="operator">-</span><span class="operator">&gt;</span>line()<span class="operator">.</span>p2());
          <span class="keyword">if</span> (endItems<span class="operator">.</span>count() <span class="operator">&amp;</span><span class="operator">&amp;</span> endItems<span class="operator">.</span>first() <span class="operator">=</span><span class="operator">=</span> line)
              endItems<span class="operator">.</span>removeFirst();

          removeItem(line);
          <span class="keyword">delete</span> line;

          <span class="keyword">if</span> (startItems<span class="operator">.</span>count() <span class="operator">&gt;</span> <span class="number">0</span> <span class="operator">&amp;</span><span class="operator">&amp;</span> endItems<span class="operator">.</span>count() <span class="operator">&gt;</span> <span class="number">0</span> <span class="operator">&amp;</span><span class="operator">&amp;</span>
              startItems<span class="operator">.</span>first()<span class="operator">-</span><span class="operator">&gt;</span>type() <span class="operator">=</span><span class="operator">=</span> DiagramItem<span class="operator">::</span>Type <span class="operator">&amp;</span><span class="operator">&amp;</span>
              endItems<span class="operator">.</span>first()<span class="operator">-</span><span class="operator">&gt;</span>type() <span class="operator">=</span><span class="operator">=</span> DiagramItem<span class="operator">::</span>Type <span class="operator">&amp;</span><span class="operator">&amp;</span>
              startItems<span class="operator">.</span>first() <span class="operator">!</span><span class="operator">=</span> endItems<span class="operator">.</span>first()) {
              DiagramItem <span class="operator">*</span>startItem <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>DiagramItem <span class="operator">*</span><span class="operator">&gt;</span>(startItems<span class="operator">.</span>first());
              DiagramItem <span class="operator">*</span>endItem <span class="operator">=</span> qgraphicsitem_cast<span class="operator">&lt;</span>DiagramItem <span class="operator">*</span><span class="operator">&gt;</span>(endItems<span class="operator">.</span>first());
              Arrow <span class="operator">*</span>arrow <span class="operator">=</span> <span class="keyword">new</span> Arrow(startItem<span class="operator">,</span> endItem);
              arrow<span class="operator">-</span><span class="operator">&gt;</span>setColor(myLineColor);
              startItem<span class="operator">-</span><span class="operator">&gt;</span>addArrow(arrow);
              endItem<span class="operator">-</span><span class="operator">&gt;</span>addArrow(arrow);
              arrow<span class="operator">-</span><span class="operator">&gt;</span>setZValue(<span class="operator">-</span><span class="number">1000.0</span>);
              addItem(arrow);
              arrow<span class="operator">-</span><span class="operator">&gt;</span>updatePosition();
          }
      }
      line <span class="operator">=</span> <span class="number">0</span>;
      <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span><span class="operator">::</span>mouseReleaseEvent(mouseEvent);
  }

  bool DiagramScene<span class="operator">::</span>isItemChange(<span class="type">int</span> type)
  {
      foreach (<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span>item<span class="operator">,</span> selectedItems()) {
          <span class="keyword">if</span> (item<span class="operator">-</span><span class="operator">&gt;</span>type() <span class="operator">=</span><span class="operator">=</span> type)
              <span class="keyword">return</span> <span class="keyword">true</span>;
      }
      <span class="keyword">return</span> <span class="keyword">false</span>;
  }

</pre>
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<!-- @@@graphicsview/diagramscene/diagramscene.cpp -->
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